boto3.py

import boto3
s3_resource = boto3.resource('s3',
        region_name            = "us-east-1" ,
        endpoint_url           =  "zzzzzzzzzzzzzzzzzzzz" ,
        aws_access_key_id      =  "uuuuuuuuuuuuuuuuuu",
        aws_secret_access_key  = "xxxxxxxxxxxxxxxxxxxxxxxxxxx"

          )
bucket_name =   "uuuuu"
bucket = s3_resource.Bucket(bucketName)
for file in files_to_upload:
        print('upload to R2 '+file)
        bucket.upload_file(file, file)